A preliminary study of subfossil Cladocera from the bottom sediments of Lake Bolshoe Miassovo (Southern Urals, Russia)

Abstract

An analysis of subfossil cladocerans from the sediment core of Lake Bolshoe Miassovo (Southern Urals) was conducted. In all, 38 cladoceran taxa from 7 families were identified. Most of them fell within the family Chydoridae. Yet, another family, Bosminidae, turned out to be represented by the largest number of individuals. The assemblage was dominated by Bosmina (Eubosmina) longispina. Relatively high concentrations were also characteristic of the Daphnia longispina gr., Chydorus сf. sphaericus, and Alona quadrangularis. The age of the studied core spans the Late glacial and entire Holocene, the maximum age of the sediment core was 13.5 yr BP (Valieva et al., 2023). In the lower layers of the core at the beginning of the Holocene, the discovered Cladocera remains were few and characterized by low species richness. The most significant transformations in the Cladocera community occurred at the end of the Late Dryas - beginning of the Holocene (11400-11950 cal. yr BP), indicating substantial changes in environmental conditions.